Remediation technology and process for heavy metal and organic matter composite contaminated soil

Abstract

The invention provides a method for remediating heavy metal-organic matter composite contaminated soil. The method sequentially comprises the steps of building a leaching slope, paving the soil, carrying out heterogeneous physical and chemical leaching, backfilling, carrying out in-situ biodegradation and carrying out phytoremediation. According to the method, contaminants in the soil can be rapidly and effectively degraded, the remediation period of the contaminated soil is shortened, the remediation cost is low, no secondary contamination is caused, the method is simple and feasible, the fertility of the soil in contaminated sites can be improved, and the method is suitable for remediating the contaminated sites with various scale. The method can be used for remediating the soil contaminated by heavy metal such as Mn, Pb, As and Cu and the soil compositely contaminated by the organic matter such as petroleum and polycyclic aromatic hydrocarbon.

Description

technical field [0001] The invention belongs to the field of remediation of polluted soil, and in particular relates to a remediation technology for compound polluted soil of heavy metals and organic matter. Background technique [0002] In recent years, with the continuous advancement of my country's industrialization and urbanization, while improving people's living standards, it has also caused serious pollution to the foundation of human survival - the soil. Soil pollution includes inorganic pollution and organic pollution. Heavy metal pollution belongs to inorganic pollution, which mainly comes from the increase of heavy metal content in soil caused by human activities. It is non-degradable and highly mobile, and it takes a long time for natural purification; petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs ) pollution belongs to organic pollution, which mainly comes from the chemical industry, transportation, etc. Among them, PAHs are carcinogenic, te...

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Problems solved by technology

However, the eluents used in the current research have certain limitations.

Utilize diethylamine tetraacetic acid sodium (Na 2 EDTA) solution is used as a leaching agent to wash heavy metal-contaminated soil, effectively remove cadmium and lead in the soil, and utilize Na 2 S·9H 2 O to precipitate heavy metals in the filtrate, making Na 2 EDTA is released again, so that the eluent can be recycled, reducing the cost of rinsing, but Na 2 EDTA has poor biodegradability and will cause secondary pollution of soil

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